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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Cyrix MediaGX and NatSemi Geode Suspend Modulation
3 * (C) 2002 Zwane Mwaikambo <zwane@commfireservices.com>
4 * (C) 2002 Hiroshi Miura <miura@da-cha.org>
5 * All Rights Reserved
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
Dave Jones32ee8c32006-02-28 00:43:23 -05009 * version 2 as published by the Free Software Foundation
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
11 * The author(s) of this software shall not be held liable for damages
12 * of any nature resulting due to the use of this software. This
13 * software is provided AS-IS with no warranties.
Dave Jones32ee8c32006-02-28 00:43:23 -050014 *
Simon Arlott27b46d72007-10-20 01:13:56 +020015 * Theoretical note:
Linus Torvalds1da177e2005-04-16 15:20:36 -070016 *
17 * (see Geode(tm) CS5530 manual (rev.4.1) page.56)
18 *
19 * CPU frequency control on NatSemi Geode GX1/GXLV processor and CS55x0
Simon Arlott27b46d72007-10-20 01:13:56 +020020 * are based on Suspend Modulation.
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 *
22 * Suspend Modulation works by asserting and de-asserting the SUSP# pin
23 * to CPU(GX1/GXLV) for configurable durations. When asserting SUSP#
Dave Jones32ee8c32006-02-28 00:43:23 -050024 * the CPU enters an idle state. GX1 stops its core clock when SUSP# is
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 * asserted then power consumption is reduced.
26 *
Dave Jones32ee8c32006-02-28 00:43:23 -050027 * Suspend Modulation's OFF/ON duration are configurable
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 * with 'Suspend Modulation OFF Count Register'
29 * and 'Suspend Modulation ON Count Register'.
Dave Jones32ee8c32006-02-28 00:43:23 -050030 * These registers are 8bit counters that represent the number of
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 * 32us intervals which the SUSP# pin is asserted(ON)/de-asserted(OFF)
32 * to the processor.
33 *
Dave Jones32ee8c32006-02-28 00:43:23 -050034 * These counters define a ratio which is the effective frequency
35 * of operation of the system.
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 *
37 * OFF Count
38 * F_eff = Fgx * ----------------------
39 * OFF Count + ON Count
40 *
41 * 0 <= On Count, Off Count <= 255
42 *
Dave Jones32ee8c32006-02-28 00:43:23 -050043 * From these limits, we can get register values
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 *
45 * off_duration + on_duration <= MAX_DURATION
46 * on_duration = off_duration * (stock_freq - freq) / freq
47 *
Dave Jones32ee8c32006-02-28 00:43:23 -050048 * off_duration = (freq * DURATION) / stock_freq
49 * on_duration = DURATION - off_duration
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 *
51 *
52 *---------------------------------------------------------------------------
53 *
54 * ChangeLog:
Dave Jones32ee8c32006-02-28 00:43:23 -050055 * Dec. 12, 2003 Hiroshi Miura <miura@da-cha.org>
56 * - fix on/off register mistake
57 * - fix cpu_khz calc when it stops cpu modulation.
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 *
Dave Jones32ee8c32006-02-28 00:43:23 -050059 * Dec. 11, 2002 Hiroshi Miura <miura@da-cha.org>
60 * - rewrite for Cyrix MediaGX Cx5510/5520 and
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 * NatSemi Geode Cs5530(A).
62 *
63 * Jul. ??, 2002 Zwane Mwaikambo <zwane@commfireservices.com>
64 * - cs5530_mod patch for 2.4.19-rc1.
65 *
66 *---------------------------------------------------------------------------
67 *
68 * Todo
69 * Test on machines with 5510, 5530, 5530A
70 */
71
72/************************************************************************
73 * Suspend Modulation - Definitions *
74 ************************************************************************/
75
76#include <linux/kernel.h>
Dave Jones32ee8c32006-02-28 00:43:23 -050077#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070078#include <linux/init.h>
79#include <linux/smp.h>
80#include <linux/cpufreq.h>
81#include <linux/pci.h>
Dave Jones00f6a232009-01-17 23:06:57 -050082#include <linux/errno.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090083#include <linux/slab.h>
Dave Jones00f6a232009-01-17 23:06:57 -050084
Andi Kleenfa8031a2012-01-26 00:09:12 +010085#include <asm/cpu_device_id.h>
Juergen Beisertf25f64e2007-07-22 11:12:38 +020086#include <asm/processor-cyrix.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88/* PCI config registers, all at F0 */
Dave Jones32ee8c32006-02-28 00:43:23 -050089#define PCI_PMER1 0x80 /* power management enable register 1 */
90#define PCI_PMER2 0x81 /* power management enable register 2 */
91#define PCI_PMER3 0x82 /* power management enable register 3 */
92#define PCI_IRQTC 0x8c /* irq speedup timer counter register:typical 2 to 4ms */
93#define PCI_VIDTC 0x8d /* video speedup timer counter register: typical 50 to 100ms */
94#define PCI_MODOFF 0x94 /* suspend modulation OFF counter register, 1 = 32us */
95#define PCI_MODON 0x95 /* suspend modulation ON counter register */
96#define PCI_SUSCFG 0x96 /* suspend configuration register */
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
98/* PMER1 bits */
Dave Jones32ee8c32006-02-28 00:43:23 -050099#define GPM (1<<0) /* global power management */
100#define GIT (1<<1) /* globally enable PM device idle timers */
101#define GTR (1<<2) /* globally enable IO traps */
102#define IRQ_SPDUP (1<<3) /* disable clock throttle during interrupt handling */
103#define VID_SPDUP (1<<4) /* disable clock throttle during vga video handling */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
105/* SUSCFG bits */
Dave Jones32ee8c32006-02-28 00:43:23 -0500106#define SUSMOD (1<<0) /* enable/disable suspend modulation */
Simon Arlott27b46d72007-10-20 01:13:56 +0200107/* the below is supported only with cs5530 (after rev.1.2)/cs5530A */
Dave Jones32ee8c32006-02-28 00:43:23 -0500108#define SMISPDUP (1<<1) /* select how SMI re-enable suspend modulation: */
109 /* IRQTC timer or read SMI speedup disable reg.(F1BAR[08-09h]) */
110#define SUSCFG (1<<2) /* enable powering down a GXLV processor. "Special 3Volt Suspend" mode */
Simon Arlott27b46d72007-10-20 01:13:56 +0200111/* the below is supported only with cs5530A */
Dave Jones32ee8c32006-02-28 00:43:23 -0500112#define PWRSVE_ISA (1<<3) /* stop ISA clock */
113#define PWRSVE (1<<4) /* active idle */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115struct gxfreq_params {
116 u8 on_duration;
117 u8 off_duration;
118 u8 pci_suscfg;
119 u8 pci_pmer1;
120 u8 pci_pmer2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 struct pci_dev *cs55x0;
122};
123
124static struct gxfreq_params *gx_params;
125static int stock_freq;
126
127/* PCI bus clock - defaults to 30.000 if cpu_khz is not available */
Dave Jones00f6a232009-01-17 23:06:57 -0500128static int pci_busclk;
129module_param(pci_busclk, int, 0444);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
131/* maximum duration for which the cpu may be suspended
132 * (32us * MAX_DURATION). If no parameter is given, this defaults
Dave Jones32ee8c32006-02-28 00:43:23 -0500133 * to 255.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 * Note that this leads to a maximum of 8 ms(!) where the CPU clock
135 * is suspended -- processing power is just 0.39% of what it used to be,
136 * though. 781.25 kHz(!) for a 200 MHz processor -- wow. */
137static int max_duration = 255;
Dave Jones00f6a232009-01-17 23:06:57 -0500138module_param(max_duration, int, 0444);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
140/* For the default policy, we want at least some processing power
141 * - let's say 5%. (min = maxfreq / POLICY_MIN_DIV)
142 */
143#define POLICY_MIN_DIV 20
144
145
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146/**
Dave Jones32ee8c32006-02-28 00:43:23 -0500147 * we can detect a core multipiler from dir0_lsb
148 * from GX1 datasheet p.56,
149 * MULT[3:0]:
150 * 0000 = SYSCLK multiplied by 4 (test only)
151 * 0001 = SYSCLK multiplied by 10
152 * 0010 = SYSCLK multiplied by 4
153 * 0011 = SYSCLK multiplied by 6
154 * 0100 = SYSCLK multiplied by 9
155 * 0101 = SYSCLK multiplied by 5
156 * 0110 = SYSCLK multiplied by 7
157 * 0111 = SYSCLK multiplied by 8
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 * of 33.3MHz
159 **/
160static int gx_freq_mult[16] = {
161 4, 10, 4, 6, 9, 5, 7, 8,
162 0, 0, 0, 0, 0, 0, 0, 0
163};
164
165
166/****************************************************************
Dave Jones32ee8c32006-02-28 00:43:23 -0500167 * Low Level chipset interface *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 ****************************************************************/
169static struct pci_device_id gx_chipset_tbl[] __initdata = {
Peter Huewe55c789b2010-07-15 20:36:41 +0200170 { PCI_VDEVICE(CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY), },
171 { PCI_VDEVICE(CYRIX, PCI_DEVICE_ID_CYRIX_5520), },
172 { PCI_VDEVICE(CYRIX, PCI_DEVICE_ID_CYRIX_5510), },
Dave Jones32ee8c32006-02-28 00:43:23 -0500173 { 0, },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174};
Alan Coxb3012e12012-01-30 14:47:28 +0000175MODULE_DEVICE_TABLE(pci, gx_chipset_tbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
Dave Jones00f6a232009-01-17 23:06:57 -0500177static void gx_write_byte(int reg, int value)
178{
179 pci_write_config_byte(gx_params->cs55x0, reg, value);
180}
181
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182/**
Dave Jones32ee8c32006-02-28 00:43:23 -0500183 * gx_detect_chipset:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 *
185 **/
186static __init struct pci_dev *gx_detect_chipset(void)
187{
188 struct pci_dev *gx_pci = NULL;
189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 /* detect which companion chip is used */
Kulikov Vasiliyccc56382010-07-03 20:03:55 +0400191 for_each_pci_dev(gx_pci) {
Dave Jones32ee8c32006-02-28 00:43:23 -0500192 if ((pci_match_id(gx_chipset_tbl, gx_pci)) != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 return gx_pci;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 }
195
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200196 pr_debug("error: no supported chipset found!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 return NULL;
198}
199
200/**
Dave Jones32ee8c32006-02-28 00:43:23 -0500201 * gx_get_cpuspeed:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 *
Dave Jones00f6a232009-01-17 23:06:57 -0500203 * Finds out at which efficient frequency the Cyrix MediaGX/NatSemi
204 * Geode CPU runs.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 */
206static unsigned int gx_get_cpuspeed(unsigned int cpu)
207{
Dave Jones32ee8c32006-02-28 00:43:23 -0500208 if ((gx_params->pci_suscfg & SUSMOD) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 return stock_freq;
210
Dave Jones32ee8c32006-02-28 00:43:23 -0500211 return (stock_freq * gx_params->off_duration)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 / (gx_params->on_duration + gx_params->off_duration);
213}
214
215/**
216 * gx_validate_speed:
217 * determine current cpu speed
Dave Jones32ee8c32006-02-28 00:43:23 -0500218 *
219 **/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
Dave Jones00f6a232009-01-17 23:06:57 -0500221static unsigned int gx_validate_speed(unsigned int khz, u8 *on_duration,
222 u8 *off_duration)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223{
224 unsigned int i;
225 u8 tmp_on, tmp_off;
226 int old_tmp_freq = stock_freq;
227 int tmp_freq;
228
Dave Jones00f6a232009-01-17 23:06:57 -0500229 *off_duration = 1;
230 *on_duration = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
Dave Jones00f6a232009-01-17 23:06:57 -0500232 for (i = max_duration; i > 0; i--) {
Dave Jones32ee8c32006-02-28 00:43:23 -0500233 tmp_off = ((khz * i) / stock_freq) & 0xff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 tmp_on = i - tmp_off;
235 tmp_freq = (stock_freq * tmp_off) / i;
236 /* if this relation is closer to khz, use this. If it's equal,
237 * prefer it, too - lower latency */
238 if (abs(tmp_freq - khz) <= abs(old_tmp_freq - khz)) {
239 *on_duration = tmp_on;
240 *off_duration = tmp_off;
241 old_tmp_freq = tmp_freq;
242 }
243 }
244
245 return old_tmp_freq;
246}
247
248
249/**
Dave Jones32ee8c32006-02-28 00:43:23 -0500250 * gx_set_cpuspeed:
251 * set cpu speed in khz.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 **/
253
254static void gx_set_cpuspeed(unsigned int khz)
255{
Dave Jones32ee8c32006-02-28 00:43:23 -0500256 u8 suscfg, pmer1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 unsigned int new_khz;
258 unsigned long flags;
259 struct cpufreq_freqs freqs;
260
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 freqs.cpu = 0;
262 freqs.old = gx_get_cpuspeed(0);
263
Dave Jones00f6a232009-01-17 23:06:57 -0500264 new_khz = gx_validate_speed(khz, &gx_params->on_duration,
265 &gx_params->off_duration);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
267 freqs.new = new_khz;
268
269 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
270 local_irq_save(flags);
271
Dave Jones00f6a232009-01-17 23:06:57 -0500272
273
274 if (new_khz != stock_freq) {
275 /* if new khz == 100% of CPU speed, it is special case */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 switch (gx_params->cs55x0->device) {
277 case PCI_DEVICE_ID_CYRIX_5530_LEGACY:
278 pmer1 = gx_params->pci_pmer1 | IRQ_SPDUP | VID_SPDUP;
279 /* FIXME: need to test other values -- Zwane,Miura */
Dave Jones00f6a232009-01-17 23:06:57 -0500280 /* typical 2 to 4ms */
281 gx_write_byte(PCI_IRQTC, 4);
282 /* typical 50 to 100ms */
283 gx_write_byte(PCI_VIDTC, 100);
284 gx_write_byte(PCI_PMER1, pmer1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
Dave Jones00f6a232009-01-17 23:06:57 -0500286 if (gx_params->cs55x0->revision < 0x10) {
287 /* CS5530(rev 1.2, 1.3) */
288 suscfg = gx_params->pci_suscfg|SUSMOD;
289 } else {
290 /* CS5530A,B.. */
291 suscfg = gx_params->pci_suscfg|SUSMOD|PWRSVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 }
293 break;
294 case PCI_DEVICE_ID_CYRIX_5520:
295 case PCI_DEVICE_ID_CYRIX_5510:
296 suscfg = gx_params->pci_suscfg | SUSMOD;
297 break;
298 default:
299 local_irq_restore(flags);
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200300 pr_debug("fatal: try to set unknown chipset.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 return;
302 }
303 } else {
304 suscfg = gx_params->pci_suscfg & ~(SUSMOD);
305 gx_params->off_duration = 0;
306 gx_params->on_duration = 0;
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200307 pr_debug("suspend modulation disabled: cpu runs 100%% speed.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 }
309
Dave Jones00f6a232009-01-17 23:06:57 -0500310 gx_write_byte(PCI_MODOFF, gx_params->off_duration);
311 gx_write_byte(PCI_MODON, gx_params->on_duration);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
Dave Jones00f6a232009-01-17 23:06:57 -0500313 gx_write_byte(PCI_SUSCFG, suscfg);
Dave Jones32ee8c32006-02-28 00:43:23 -0500314 pci_read_config_byte(gx_params->cs55x0, PCI_SUSCFG, &suscfg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315
Dave Jones32ee8c32006-02-28 00:43:23 -0500316 local_irq_restore(flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317
318 gx_params->pci_suscfg = suscfg;
319
320 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
321
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200322 pr_debug("suspend modulation w/ duration of ON:%d us, OFF:%d us\n",
Dave Jones32ee8c32006-02-28 00:43:23 -0500323 gx_params->on_duration * 32, gx_params->off_duration * 32);
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200324 pr_debug("suspend modulation w/ clock speed: %d kHz.\n", freqs.new);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325}
326
327/****************************************************************
328 * High level functions *
329 ****************************************************************/
330
331/*
Dave Jones32ee8c32006-02-28 00:43:23 -0500332 * cpufreq_gx_verify: test if frequency range is valid
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 *
Dave Jones32ee8c32006-02-28 00:43:23 -0500334 * This function checks if a given frequency range in kHz is valid
335 * for the hardware supported by the driver.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 */
337
338static int cpufreq_gx_verify(struct cpufreq_policy *policy)
339{
340 unsigned int tmp_freq = 0;
341 u8 tmp1, tmp2;
342
Dave Jones32ee8c32006-02-28 00:43:23 -0500343 if (!stock_freq || !policy)
344 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346 policy->cpu = 0;
Dave Jones00f6a232009-01-17 23:06:57 -0500347 cpufreq_verify_within_limits(policy, (stock_freq / max_duration),
348 stock_freq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349
350 /* it needs to be assured that at least one supported frequency is
351 * within policy->min and policy->max. If it is not, policy->max
352 * needs to be increased until one freuqency is supported.
Dave Jones32ee8c32006-02-28 00:43:23 -0500353 * policy->min may not be decreased, though. This way we guarantee a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 * specific processing capacity.
355 */
356 tmp_freq = gx_validate_speed(policy->min, &tmp1, &tmp2);
Dave Jones32ee8c32006-02-28 00:43:23 -0500357 if (tmp_freq < policy->min)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 tmp_freq += stock_freq / max_duration;
359 policy->min = tmp_freq;
Dave Jones32ee8c32006-02-28 00:43:23 -0500360 if (policy->min > policy->max)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 policy->max = tmp_freq;
362 tmp_freq = gx_validate_speed(policy->max, &tmp1, &tmp2);
363 if (tmp_freq > policy->max)
364 tmp_freq -= stock_freq / max_duration;
365 policy->max = tmp_freq;
366 if (policy->max < policy->min)
367 policy->max = policy->min;
Dave Jones00f6a232009-01-17 23:06:57 -0500368 cpufreq_verify_within_limits(policy, (stock_freq / max_duration),
369 stock_freq);
Dave Jones32ee8c32006-02-28 00:43:23 -0500370
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 return 0;
372}
373
374/*
Dave Jones32ee8c32006-02-28 00:43:23 -0500375 * cpufreq_gx_target:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 *
377 */
378static int cpufreq_gx_target(struct cpufreq_policy *policy,
379 unsigned int target_freq,
380 unsigned int relation)
381{
382 u8 tmp1, tmp2;
383 unsigned int tmp_freq;
384
Dave Jones32ee8c32006-02-28 00:43:23 -0500385 if (!stock_freq || !policy)
386 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387
388 policy->cpu = 0;
389
390 tmp_freq = gx_validate_speed(target_freq, &tmp1, &tmp2);
391 while (tmp_freq < policy->min) {
392 tmp_freq += stock_freq / max_duration;
393 tmp_freq = gx_validate_speed(tmp_freq, &tmp1, &tmp2);
394 }
395 while (tmp_freq > policy->max) {
396 tmp_freq -= stock_freq / max_duration;
397 tmp_freq = gx_validate_speed(tmp_freq, &tmp1, &tmp2);
398 }
399
400 gx_set_cpuspeed(tmp_freq);
401
402 return 0;
403}
404
405static int cpufreq_gx_cpu_init(struct cpufreq_policy *policy)
406{
407 unsigned int maxfreq, curfreq;
408
409 if (!policy || policy->cpu != 0)
410 return -ENODEV;
411
412 /* determine maximum frequency */
Dave Jones00f6a232009-01-17 23:06:57 -0500413 if (pci_busclk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 maxfreq = pci_busclk * gx_freq_mult[getCx86(CX86_DIR1) & 0x0f];
Dave Jones00f6a232009-01-17 23:06:57 -0500415 else if (cpu_khz)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 maxfreq = cpu_khz;
Dave Jones00f6a232009-01-17 23:06:57 -0500417 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 maxfreq = 30000 * gx_freq_mult[getCx86(CX86_DIR1) & 0x0f];
Dave Jones00f6a232009-01-17 23:06:57 -0500419
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 stock_freq = maxfreq;
421 curfreq = gx_get_cpuspeed(0);
422
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200423 pr_debug("cpu max frequency is %d.\n", maxfreq);
424 pr_debug("cpu current frequency is %dkHz.\n", curfreq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
426 /* setup basic struct for cpufreq API */
427 policy->cpu = 0;
428
429 if (max_duration < POLICY_MIN_DIV)
430 policy->min = maxfreq / max_duration;
431 else
432 policy->min = maxfreq / POLICY_MIN_DIV;
433 policy->max = maxfreq;
434 policy->cur = curfreq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 policy->cpuinfo.min_freq = maxfreq / max_duration;
436 policy->cpuinfo.max_freq = maxfreq;
437 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
438
439 return 0;
440}
441
Dave Jones32ee8c32006-02-28 00:43:23 -0500442/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 * cpufreq_gx_init:
444 * MediaGX/Geode GX initialize cpufreq driver
445 */
Linus Torvalds221dee22007-02-26 14:55:48 -0800446static struct cpufreq_driver gx_suspmod_driver = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 .get = gx_get_cpuspeed,
448 .verify = cpufreq_gx_verify,
449 .target = cpufreq_gx_target,
450 .init = cpufreq_gx_cpu_init,
451 .name = "gx-suspmod",
452 .owner = THIS_MODULE,
453};
454
455static int __init cpufreq_gx_init(void)
456{
457 int ret;
458 struct gxfreq_params *params;
459 struct pci_dev *gx_pci;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460
461 /* Test if we have the right hardware */
Dave Jones00f6a232009-01-17 23:06:57 -0500462 gx_pci = gx_detect_chipset();
463 if (gx_pci == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 return -ENODEV;
465
466 /* check whether module parameters are sane */
467 if (max_duration > 0xff)
468 max_duration = 0xff;
469
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200470 pr_debug("geode suspend modulation available.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
Dave Jones84f0b1e2006-03-11 16:13:56 -0500472 params = kzalloc(sizeof(struct gxfreq_params), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 if (params == NULL)
474 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475
476 params->cs55x0 = gx_pci;
477 gx_params = params;
478
479 /* keep cs55x0 configurations */
480 pci_read_config_byte(params->cs55x0, PCI_SUSCFG, &(params->pci_suscfg));
481 pci_read_config_byte(params->cs55x0, PCI_PMER1, &(params->pci_pmer1));
482 pci_read_config_byte(params->cs55x0, PCI_PMER2, &(params->pci_pmer2));
483 pci_read_config_byte(params->cs55x0, PCI_MODON, &(params->on_duration));
Dave Jones00f6a232009-01-17 23:06:57 -0500484 pci_read_config_byte(params->cs55x0, PCI_MODOFF,
485 &(params->off_duration));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486
Dave Jones00f6a232009-01-17 23:06:57 -0500487 ret = cpufreq_register_driver(&gx_suspmod_driver);
488 if (ret) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 kfree(params);
490 return ret; /* register error! */
491 }
492
493 return 0;
494}
495
496static void __exit cpufreq_gx_exit(void)
497{
498 cpufreq_unregister_driver(&gx_suspmod_driver);
499 pci_dev_put(gx_params->cs55x0);
500 kfree(gx_params);
501}
502
Dave Jones00f6a232009-01-17 23:06:57 -0500503MODULE_AUTHOR("Hiroshi Miura <miura@da-cha.org>");
504MODULE_DESCRIPTION("Cpufreq driver for Cyrix MediaGX and NatSemi Geode");
505MODULE_LICENSE("GPL");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506
507module_init(cpufreq_gx_init);
508module_exit(cpufreq_gx_exit);
509